Cable television systems are well-known and widely used for delivering high quality video to home televisions. Subscribers of cable television services are offered a broad array of programs, including traditional broadcast programs and special made-for-cable programs. Cable television services also offer some selective services in which a viewer can order by telephone to watch a special program. An example of this type of service is Pay-Per-View.RTM..
Newer, interactive television (ITV) systems expand the assortment of services that can be provided to a viewer's home. ITV systems have a computerized control center, known as the "headend", which interactively communicates with multiple distributed television units located in subscriber homes, thereby allowing subscribers to order or select services from their own televisions. ITV systems offer the same traditional services of familiar cable television as well as a variety of new additional interactive services, such as on-demand applications. Examples of on-demand applications include video-on-demand which permits a viewer to order videos and watch them at his/her own time schedule, home shopping applications which enables a viewer to browse various stores and catalogs on TV and order products from home, and financial applications which allow a viewer to conduct banking and other financial transactions using the television.
During operation of ITV systems, it is desirable to record events reflecting operation of the system. There are several reasons for logging events, including to monitor system operation, detect system errors, and derive statistical data. This latter reason is particularly beneficial for monitoring usage patterns for resource planning and marketing information. For example, a system operator in charge of providing the programming to the subscribers might be interested in certain viewer usage patterns, such as what shows the viewer watches, how often the viewer tunes in, how frequently the viewer changes channels, and so forth. Merchants offering video catalogs over the ITV system might be interested in viewer shopping patterns, such as how often viewers used the home shopping application, how many viewers opened a particular merchant's catalog, what items in the catalog attracted the most attention, whether viewers returned to browse the same catalog multiple times, and so on.
The process of recording events is referred to as "event logging", a terminology adopted from the meticulous practice that a ship's captain uses to enter daily notes during a sea voyage. In the electronic world, events are logged in storage devices and later used in statistical analysis to derive some desired information concerning usage and operation of the system.
Some computer operating systems have an event logging component. The operating system Windows NT.RTM. from Microsoft Corporation logs events which reflect operation of the computer system. The events are logged locally to a storage, such as the hard disk drive, that is resident on the same computer that the operating system is running. The Windows NT.RTM. event logging process can also be conducted over a network, wherein events are logged on another computer remote from the host computer where the event arises. To accommodate remote logging, however, the host computer must know the remote computer to-which events are logged.
Conventional event logging procedures are not well suited for the ITV environment. Given the vast size of the ITV system, it is difficult for a logging component at the headend to track all of the distributed television units with respect to their events.
Accordingly, there is a need to design an event logging system that can be used in the interactive television environment that (1) offers global, centralized logging at the headend; (2) enables the logging facilities to be conveniently relocated within the headend without disrupting the logging process; and (3) a very large number and high frequency of events from the many televisions units.